Diaphragm valve



Patented June 21, 1938 ,izso

music L McNeal,

The Whonse Erase @QEWW Wilmen-ding, Pan a. coration of Peyivania Application 3 an 13,

(or. Edi-M119) This invention relates to valve structures, and more particularly to a diaphragm valve device adapted to control the now of fluid under pressure.

In operating a diaphragm valve device of the type employing a flexible diaphragm having on. one side a. valve-seat portion which is adapted to be urged into sealing engagement with a suitable seat for shutting oi the flow of fluid under pres- 'sure, a considerable load or force must sometimes be applied to the back of the diaphragm in order to close the'valve, as for instance, when said diaphragm is moved against an opposing fluid pressure. The force required for urging the valve against the seat may be so great as to cause undesirable distortion of the diaphragm and cheating or cutting of the valve seat portion, thereby preventing the tight seating action thereof.

The principal object of my invention is to provide an improved diaphragm valve structure having means for obviating the above dificuity.

Another object of my invention is to provide an inexpensive diaphragm valve structure having means for supporting the diaphragm independently of the valve seat portion, so as to. prevent excessive, displacement and possible cutting of said diaphragm when a heavy pressure is applied to the diaphragm for pressing said valve seat portion against the seat. i

In the accompanying drawing, Fig. l is a sectional View of a diaphragm. valve device embodying the invention, and Fig. 2 is a plan view taken on the line 2-2 of Fig. 1.

As shown in the drawing, the diaphragm valve device may comprise a flexible diap'magm i which is clamped between easing sections 2 and 3, said casing sections being secured together by any suitable means such as bolts (not shown). Disposed at the central portion or" the cnaphragm is an annular seating portion or head 5 formed on one side of the diaphragm, and an enlarged boss portion 5 is formed on the side opposite said seat head, so as to afiord the desired degreeof co rigidity to the valve portion. Formed in the casing section 2 on one side of the diaphragm i is a chamber '5 containing biasing means for -loading said diaphragm in the form of a. coil spring ii, which extends intoa recess formedin dil'the wall d and is interposed between said wall and a follower member it which engages the diaphragm i. The chamber l maybe open to the atmosphere by way of a passage it. The foilower member has a recessed or dished portion for is receiving the boss portion 6 of the diaphragm it 1936, Semi No. 59

which is thus held against lateral movement relative to said follower member.

A valve chamber it is formed in the casing section 3 at the seating side of the diaphragm i, said valvechamber being connected to a passage it. Mounted in a countersunk bore in the casing section 3 is a valve seat member to, which has a central opening connected to a. passage is in said casing section. An annular seat rib Ed is provided on the seat member surrounding the open- 10 ing i'l, said seat rib being aligned for engagement with the annular seat head 5 on the valve portion of the diaphragm i.

According to my invention, diaphragm supporting shoulders it are provided on the seat member it, said shoulders being formed as segments of an annulus surrounding the seat rib 2d and preferably projecting somewhat above the said seat rib. The space 22 intermediate the seat rib 2t and the shoulders 25 is always open to the valve chamber 6% by way of the radial grooves 23 separating said shoulders.

The spring 8 acts downwardly on the follower it and diaphragm 5 so as normally to urge the seat head into engagement with the valve seat rib 2%, cutting ofi communication between the valve chamber it and the passage id. When fluid pressure acting in the chamber iii is increased suiilciently to overcome the spring d, the diaphragm i is moved upwardly, moving the seat head it away from the seat rib 2B and permitting fluid under pressure to flow from said chamber through the opening i! to the passage iii.

It will be apparent that if, when the pressure of fluid is reduced in chamber t3, the spring should exert sumcient pressure to cause distortion of the seat head 5, such distortion will be limited by the engagement of the shoulders 26 with the diaphragm.

While one illustrative embodiment of the invention has been described in detail, it is not my intention to limit its scope to thahembodiment or otherwise than by the terms of the appended claim.

Having now described my invention, what I 5 claim as new and desire to secure by Letters Patent, is:

A diaphragm valve device comprising a casing,

a flemble diaphragm mounted in the casing, said diaphragm having a centrally disposed ho'ss porac tion formed on one side and an annular seat bead carried on the other side concentrically of said boss portion, a rigidiollower member engaging said diaphragm and having a central recess for receiving said boss portion, an arm seat assocg ciated with said casing and engageable by the seat bead. and an annulansegmented shoulder surrounding the seat and disposed opposite a portion of the diaphragm outwardly of the boss portion, said segmented shoulder being spaced from said diaphragm upon initial engagement of the seat bead with said seat, and engageable by said diaphragm when the seat bead. is distorted under pressure applied to said diaphragm through the medium of the follower member, whereby the pressure on said diaphragm is distributed for limiting the extent of distortion thereof in the region of the boss portion.

DONALD L. MCNEAL. 

